ABSTRACT
Covering the period from the first month of the first year of Chongzhen to the second month of the fourth year; records of twenty-nine days; altogether seventy-one topics. A certain licentiate named Xue had since long been admiring the Holy Doctrine, but he let matters drift and never made a firm decision. On the twelfth at noon he paid a call on Master Ai, who most earnestly tried to persuade and encourage him as much as he could. From the autumn equinox till the spring equinox the sun circles the lower hemisphere, and its light never reaches the region under the north pole, so during that half year it always is night and there is no daylight. For the region under the south pole it is just the opposite. The movement imparted to it as it is carried along by the sphere of Prime Movement goes from east to west at a high speed.
